Automatic fire-alarm.



PATENTED FEB. 13, 1906.

A. TAYLOR.

AUTOMATIC FIRE ALARM.

APPLICATION FILED MAY13, 1905.

INVENTOR WITNESSES:

UNITED STATES PATENT OFFICE.

THOMAS HENDERSON HORNE, OF VICTORIA, oANADA. 'AUTOIVVI-IA'TIC FIRE-ALARM.

Specification of Letters Itatent.

Patented Feb. 13, 1906.

Application filed my 13,1906; Serial No. 260,327.

To all whom may concern:

Be it known that I, ALFRED TAYLOR, a'citizen of the Dominion of Canada, residing at the city of Victoria, in the Province of British Columbia, Canada, have invented a new and useful Improvement in Automatic Fire-Alarms,

of which the following is a specification.

This invention relates to an automatic firealarm of that class wherein the expansion under heat of a volatile material is used to establish contact in an electric-bell circuit, whereby an alarm may be given; and the invention consists, primarily, inthe particular design of the chamber in which the volatile material is retained, whereby the expansion of it under heat produces an axial extension of the chamber in a series of intermitv I tent movements as the internal ressure 1ncreases. By this intermittent eature the adjustment of the device to effect an alarm may be better regulated to any desired temperature, and when such temperature is.

reached the contact by which the circuit is opened to ring the alarm is immediate and complete and the alarm consequently more effectual. In other fire-alarms operated by expansion b heat the contact being gradually attains the ring is at first feebleand the ear of a sleeper becomes accustomed to the sound before it attains its full strength, and

the value of the alarm is consequently less than if a ring of full strength were given at once,

A further and important advantage of the design lies I the fact that it is susceptible of being introduced into .the structure of an ordinary electric-bell push, so that an automatic fire-alarm system ma be grafted onto a. bell-signaling system an the expense of separate instal atlon avoided. The value of time feature will be readily appreciated in build such as factories, warehouses, hotels, c. requiring a call system.

' The invention is fully described in the following s ecification and illustrated in. the drawings w ich accompany it.

Figure -1 is a cross-section on the line A A in Fig. 2 of my device in aform which may be appropriately secured to the ceiling or upper' part of the wall of a room; Fig. 2, a lan of the .same' from the under side, and ig. '3 a crosssection showin the device as applied to an ordinary electric-bell push.

In the drawings, 2 represents a shallow cythe necessary lation and lindrical metallic vessel within which is hermetically sealed a volatile material which at the desired limit of temperature will afford expansion to efi'ect the purpose. The ends. 3 Off/i118 chamber 2 are edge-bound to a sufficient extent to impart a slight con vexity to them, (the amount of which is exaggerated in the drawings) and this convexity under normal conditions is directed inward, as shown by the full lines in the drawings; but when a pressure sufficient to overcome theedge tension of the ends is generated within the chamber by the volatilization of the material therein the convexity of the ends will be bulged or forced, outward and the axial length of the chamber increased,as indicated by dot-and-dash lines in Fig. 1.

Attention is here drawn to the fact that if both ends 3 of the chamber are edge-bound as the pressure within the chamber lnc-reases one end will first be outward] bulged and the relief thus aflorded to the internal pressure willrequirea sensible further increase of pressure before the other end is forced out, an

this pause or rest in extension affords theopportunity for effective adjustment to which attention will be drawn later. further increase this'opportunity for adjustment, one or both ends 3 may be corrugated or provided with a series of annular grooves 5, as illustratedin Fig. 3, so that each end may be rovided with a series of edge-bound areas, which will successivel be acted upon as the pressure within gradh ially increases. In the application of this principle to the pu'rpose of an alarm the chamber 2 is inclosed in a casing 8, adjustably secured to a base 9, through which the terminals 10 of the electrio-bell circuit 6 are carried in suitable insu- 1project within the casing. A spring '11 ho ds the chamber 2 ofl the terminals 10 until the bulging of one or the other, or both, of the ends reacting against the end of the casing 8 overcomes the resistance of the spring 11 and presses the adjacent end 3 ofthe chamber 2 against the terminals 10,

thus,bridging the space between the terminals by the metallic end of the chamber and opening the circuit in-which is the electric bell. a

The base 9 will preferably be made of insulating material to which the casing can ap ropriatblybe attachedbyascrewthread,w 'ch means of attachment will afford the desired facility for adjustment, a small screw 12 being provided to enable the casing to be se-. cured at any desired position of such adjustment.

The casing 8 will preferably be made open to afford access of the external air to the material of the chamber and insure a prompt volatilization and alarm in the case of fire.

The application of the device to an electricbell push is illustrated in Fig. 3, the construction being similar to that revealed in Fig. 1, with the addition of the push-button 13 in the outer end of the casing 8, so that when required as a call-bell the chamber 2' merely acts asa contact-bridge to be pushed in by the button 13 and establish connection between the terminals 10 of the bellcircuit, while if a firebreaks out in the room the ends of the chamber 2 will be outwardly-extended and connect the terminals.

Havin =nowparticularlydescribed and ascertaine the nature of my said invention and the manner of its operation, I hereby declare that what I claim as new, and desire to be protected in by Letters Patent, is

, 1. In an automatic fire-alarm; the combination-with the terminals of an electric-bell circuit, of means for establishing a connection between the terminals and closing a circuit such means comprising, a shallow hermetically-sealed chamber having ends which are edge-bound and normally inwardly convex but susceptible of being outwardly bulged by pressure 'within the chamber, means for supporting such chamber'adjacent to the terminals so that when one or other or both of the ends are outwardly bulged the adjacent end Willelectrically connect the terminals, and means for positively and normallyholding such connecting means off both oi the terminals. g

2. In an automatic fire-alarm; the combination with the terminals of an electric-bell circuit,- of a non-conductin base throu h which the terminals outwardly and fixed y project, of an open casing adjustabl secured to the base, of a shallow hermetica 1 -sealed chamber between the base and the end of but susceptible of being outwardl the casing, the ends of which chamber are edge-bound and normally inwardly convex, but outwardly extensible under internal pressure to contact with and brid e between the terminals and close the bel -circuit, and means for normally holding such bridging means off the terminals.

3. In an automatic fire-alarm; the combination with the terminals of an electric-bell circuit, of a base of non-conducting material through which the terminals are carried, such base having a screw-thread receiving a casing designed to retain between the end of the casing and the terminals a shallow hermetically-sealed chamber the ends of which are edge-bound and normally inwardly convex, bulged to contact with the exposed termina s of the circuit, of means for normall holding the adj a-. cent end of the chamber 0 the terminals and means for securing the casing in any desired position of adjustment from .the non-conducting base.

4. In an automatic fire-alarm, the combination with an insulating-base havmg screwreceiving apertures to secure the same to a support and having a central countersunk portion, of an open frame connected with said base and supported thereby, an expandible sealed vessel held within said open frame below the base, a. coil-spring seated in said countersunk portion of the base for engaging the sealed vessel, a pair of electric terminals carried by said base, said spring serving to normally hold said sealed vessel out of contact with said terminals and a push-button carried by the open frame and in engagement with said vessel by means of which the vessel can be pushed up into enga ement with the electric terminals, substantia described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ALFRED TAYLOR.

ly as shown and Witnesses:

H. A. FREDERICK, THOMAS H. HORNE. 

